\section{Research to be undertaken under proposed award}

\label{sec:overview}                                    

The ASU Meson Physics Group played a central role
in designing, building, commissioning, and exploiting
the past and current generation of experimental facilities at JLab by
leading and collaborating in experiments in Hall B
that advanced understanding of the nucleon.
The ASU group subsequently led and participated in a program of experiments
that provided the bulk of the current database for non-strange meson photoproduction data,
which underpin the current understanding of the nucleon.
This program included the development and exploitation of polarized photon beams and polarized
proton targets. ASU-led experiments and analyses using CLAS are summarized in Table  \ref{tbl:mpg}.
(Remaining 6 GeV CLAS analyses will be completed by the start of
the requested funding period.)
\vspace{12pt}

\begin{table}[h]
\caption{\small{ASU-led research in the CLAS 6 GeV program. Citation statistics from INSPIRE (8/22/2018).
(The project marked with ``$\ast$'' has statistics insufficient for publication.)
}}
\vspace{2mm}
\centering
\begin{tabular}{|c|c|c|}
\hline
Reaction & \ Observable & \ Status [Presentations, publications]  \\
\hline
\hline
\multirow{2}{*}{$\gamma p \rightarrow p \pi^0$}
& $d\sigma/d\Omega$ & Completed. Published August 2007. \cite{Dugger:2007bt} (cited 87 times)  \\
\cline{2-3}
& $\Sigma$ &Completed. Published December 2013. \cite{Dugger:2013crn} (cited 32 times)\\
\hline
\multirow{2}{*}{$\gamma p \rightarrow n \pi^+$}
& $d\sigma/d\Omega$ & Completed.  Published June 2009. \cite{Dugger:2009pn} (cited 103 times)  \\
\cline{2-3}
& $\Sigma$ &Completed. Published December 2013. \cite{Dugger:2013crn} (cited 32 times)\\
\cline{2-3}
& $T, F$ &Analysis note being drafted. \\
\cline{2-3}
& $P, H$ &Analysis note being drafted.  \\
\hline
\multirow{2}{*}{$\gamma p \rightarrow p \eta$}
& $d\sigma/d\Omega$ & Completed. Published November 2002. \cite{Dugger:2002ft} (cited 129 times) \\
\cline{2-3}
& $\Sigma$ &Completed. Published March 2017. \cite{Collins:2017sgu} (cited 13 times). \\
\cline{2-3}
& $E$ &Completed. Published  April 2016. \cite{Senderovich:2015lek} (cited 23 times)\\
\cline{2-3}
& $T, F$ &Dissertation of Ross Tucker successfully defended April 2016. $\ast$\\
\hline
\multirow{2}{*}{$\gamma p \rightarrow p \eta^\prime$}
& $d\sigma/d\Omega$ & Completed. Published February 2006. \cite{Dugger:2005my} (cited 65 times) \\
\cline{2-3}
& $\Sigma$ &Completed. Published March 2017. \cite{Collins:2017sgu} (cited 13 times) \\
\hline
$\gamma p \rightarrow p \omega$ & $\Sigma$ &Completed. Published June 2017. \cite{Collins:2017vev} (cited 3 time\
s) \\
\hline
\end{tabular}
 \label{tbl:mpg}
\end{table}

This proposal capitalizes on the momentum and experience of the ASU group 
to pursue a vigorous experimental program with the newly-upgraded facilities at JLab.
We will use the CLAS12 detector to study multi-strange-quark baryons in Hall B, 
and will employ the GlueX detector in Hall D to search for hybrid mesons, while
also providing precise and reliable characterization of the Hall D photon beam for all Hall D
experiments using the ASU triplet polarimeter (TPOL). 


